Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itaiçaba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W T ), carapace length (L C ) and abdomen+telson length (L A+T ) and to register the number of non-ovigerous females (NOF) and ovigerous females (OF). Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L T ) of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4%) and 824 females (61.6%). The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7%) did not carry eggs in their abdomens (NOF) and 332 (40.3%) carried eggs in their abdomens (OF). There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM), rudimentary (RU), intermediary (IN) and mature (M). M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.Keywords: reproduction, reproductive cycle, Macrobrachium amazonicum. Ciclo reprodutivo de fêmeas de Macrobrachium amazonicum (Crustacea, Palaemonidae) ResumoDas espécies de camarão de água doce brasileiras, Macrobrachium amazonicum é a preferida para cultivo, devido ao seu rápido desenvolvimento e fácil manutenção em cativeiro. Este trabalho teve como objetivos caracterizar as fases do ciclo sexual e determinar a idade da primeira maturação de fêmeas de M. amazonicum, coletadas mensalmente, de junho de 2002 a maio de 2003, no Rio Jaguaribe, Itaiçaba, Ceará. Uma amostra de água do local foi coletada mensalmente para determinação dos seguintes parâmetros: temperatura, oxigênio dissolvido, pH e salinidade. Do total de indivíduos capturados mensalmente, uma amostra de fêmeas foi selecionada para determinação do peso total (W T ), do comprimento do cefalotórax (L C ) e do abdômen+telson (L A+T ), e para registro de fêmeas não ovígeras (FNO) e ovígeras (FO). A determinação macroscópica dos estágios de maturação ovariana de M. amazonicum foi realizada pela observação da coloração, do tamanho, da posição e da aparência dos ovários observados por transparência da carapa...

In Brazil, studies with native freshwater prawn species were discontinued due to great importance of Macrobrachium rosenbergii. Therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. The aim of this study was to determine the fecundity and fertility of Macrobrachium amazonicum captured monthly from June 1999 to June 2001 from Jaguaribe River, Itaiçaba, Ceará, Brazil. Prawns were collected using fishing net and transferred at Biological Science Laboratory, Ceara State University (Fortaleza, Ceará, Brazil). Among the ovigerous M. amazonicum females, 60 were randomly selected to determine fecundity. The eggs adhered to the pleopods were taken out and they were then placed in a Gilson solution, and then stored in alcohol 70%. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. To determine fertility, ovigerous M. amazonicum females were stored in individual 10 L-glass tanks maintained under strong aeration. After the hatching, the larvae were siphoned and counted. The data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. With respect to average fecundity (F) by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. As for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. The highest number of eggs observed individually per hatching was 2,193. Average fecundity/total length (L) and average fecundity/total weight (W) may be expressed by a linear relationship. The adjusted equations are: F = -411.6 + 203.1 L (p < 0.0001) and F = 566.4 + 157.3 W (p < 0.0001), respectively. In the analysis of average fertility (N) per length classes, the lowest and highest number of larvae observed was 374 and 1,301, respectively. With respect to fertility per weight classes, the lowest number of larvae was 581 and the highest, 1,391. In this work, the maximum number of larvae observed per hatching for females kept in laboratory was 2,594. Average fertility/total length and average fertility/total weight may be expressed by a linear relationship. The adjusted equations are: N = -1042.7 + 264.9 L (p < 0.0002); N = 384.1 + 160.3 W (p < 0.003). From these results we can deduced that fecundity and fertility of M. amazonicum are lower than ones commercial species, never-the-less it can be captured during all year long. The number of captured prawns was large in the months whose level of water was low; the inverse was observed in the months that the river was with a high volume of water.

In the present study, it was sought to compare yeast microbiota of wild and captive Macrobrachium amazonicum and evaluate the antifungal susceptibility and production of virulence factors by the recovered isolates of Candida spp. Additionally, cultivation water was monitored for the presence of fungi. Overall, 26 yeast isolates belonging to three genera and seven species were obtained, out of which 24 were Candida spp., with Candida famata as the most prevalent species for both wild and captive prawns. From cultivation water, 28 isolates of filamentous fungi were obtained, with Penicillium spp., Cladosporium spp. and Aspergillus spp. as the most frequent genera. Eight out of 24 Candida spp. isolates were resistant to azole derivatives, out of which four were recovered from wild-harvested prawns. As for production of virulence factors, three (12.5%) and eight (33.3%) isolates presented phospholipase and protease activity, respectively. This is the first comparative study between wild and captive prawns and the first report on yeast microbiota of M. amazonicum. The most relevant finding was the high percentage of resistant Candida spp., including from wild individuals, which suggests the occurrence of an environmental imbalance in the area where these prawns were captured.

Four 0.02-ha earthen ponds at the UNESP Aquaculture Center, Jaboticabal, S5o Paulo, Brazil, were stocked with newly metamorphosed Macrobrachium rosenbergii post-larvae at 1.5 animals/m2. After 8 mo, prawn density at harvest ranged from 0.3/ mz to 0.8/m2. Growth curves were determined for each population using von Bertalanffy growth functions. Asymptotic maximum length and asymptotic maximum weight increased as final population size decreased indicating that a strong density effect on prawn growth occurs in semi-intensive culture, even when populational density varies within a small range of less than 1 animal/mz.

Since, there is no study reporting the mechanism of azole resistance among yeasts isolated from aquatic environments; the present study aims to investigate the occurrence of antifungal resistance among yeasts isolated from an aquatic environment, and assess the efflux-pump activity of the azole-resistant strains to better understand the mechanism of resistance for this group of drugs. For this purpose, monthly water and sediment samples were collected from Catú Lake, Ceará, Brazil, from March 2011 to February 2012. The obtained yeasts were identified based on morphological and biochemical characteristics. Of the 46 isolates, 37 were Candida spp., 4 were Trichosporon asahii, 3 were Cryptococcus laurentii, 1 Rhodotorula mucilaginosa, and 1 was Kodamaea ohmeri. These isolates were subjected to broth microdilution assay with amphotericin B, itraconazole, and fluconazole, according to the methodology standardized by the Clinical and Laboratory Standards Institute (CLSI). The minimum inhibitory concentrations (MICs) of amphotericin B, itraconazole, and fluconazole were 0.03125–2 μg/mL, 0.0625 to ≥16 μg/mL, and 0.5 to ≥64 μg/mL, respectively, and 13 resistant azole-resistant Candida isolates were detected. A reduction in the azole MICs leading to the phenotypical reversal of the azole resistance was observed upon addition of efflux-pump inhibitors. These findings suggest that the azole resistance among environmental Candida spp. is most likely associated with the overexpression of efflux-pumps.